Since the discovery of carbon nanotubes in 1991 [Iijima, Nature, 354, pp. 56-58, 1991] and single-wall carbon nanotubes in 1993 [Iijima et al., Nature, 363, pp. 603-605, 1993; Bethune et al., Nature, 363, pp. 605-607, 1993], research has been conducted to exploit their unique mechanical, electrical, and thermal properties to create multifunctional composite materials [Barrera, J. of Mater., 52, pp. 38-42, 2000]. Previous research has shown that single-wall carbon nanotubes have the highest conductivity of any known fiber [Thess et al., Science, 273, pp. 483-487, 1996], a higher thermal conductivity than diamond [Hone et al., Appl. Phys. Lett., 77, pp. 666-668, 2000], and the highest stiffness of any known fiber [Yu et al., Phys. Rev. Lett., 84, pp. 5552-5555, 2000.
Due to the provocative geometry and other remarkable properties of carbon nanotubes, they are of considerable interest to the aerospace and radiation communities [O'Rourke, J. Mater. Res., 17(10), 2002; Klimov et al., Physics Letters A, 226, pp. 244-252, 1997; Cui et al., Physics Letters A, 295, pp. 55-59, 2002; Salonen et al., Nuclear Instruments and Method in Physics Research B, 193, pp. 603-608, 2002]. The possibility of nanotubes serving as a storage medium for hydrogen [Ye et al., Appl. Phys. Lett, 74(16), pp. 2307-2309, 1999] is of particular interest for future spacecraft (e.g., fuel cells), and hydrogen-rich and other low atomic mass materials are believed to minimize radiation exposure in space environments [Wilson et al. (Eds.), Shielding Strategies for Human Space Exploration, NASA Conference publication 3360, pp. 17-28, 1997].
Efforts to exploit carbon nanotube properties invariably rely on the ability to manipulate and homogeneously disperse carbon nanotubes in other host materials and/or matrices. Such manipulability can be facilitated by chemical modification of the carbon nanotube ends [Liu et al., Science, 280, pp. 1253-1256, 1998; Chen et al., Science, 282, pp. 95-98, 1998] and/or sidewalls [Bahr et al., J. Am. Chem. Soc., 123, pp. 6536-6542, 2001; Holzinger et al., Angew. Chem. Int. Ed., 40(21), pp. 4002-4005, 2001; Khabashesku et al., Acc. Chem. Res., 35, 1087-1095, 2002] of the carbon nanotubes. However, for many applications, such as those requiring highly conductive carbon nanotubes, the chemically modified or functionalized carbon nanotubes are unsuitable for the final product. Current techniques of chemically [Mickelson et al., J. Phys. Chem. B, 103, pp. 4318-4322, 1999] and thermally [Boul et al., Chem. Phys. Lett., 310, pp. 367-372, 1999; Bahr et al., J. Am. Chem. Soc., 123, pp. 6536-6542, 2001] defunctionalizing functionalized carbon nanotubes place severe restrictions on the types of other materials used in the various substrates, devices, and composite/blended materials originally comprising the functionalized carbon nanotubes.